Purpose: Alterations in DNA damage repair (DDR) pathway genes occur in 20-25% of men with metastatic castration-resistant prostate cancer (mCRPC). Although poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) have been shown to benefit men with mCRPC harboring DDR defects due to mutations in BRCA1/2 and ATM, additional treatments are necessary because the effects are not durable.
Experimental Design:We performed transcriptomic analysis of publicly available mCRPC cases, comparing BRCA2-null to BRCA2 wild type. We generated BRCA2-null prostate cancer cells using CRISPR/Cas9 and treated these cells with PARPi and SRC inhibitors. We also assessed the antiproliferative effects of combination treatment in 3D prostate cancer organoids.
Results:We observed significant enrichment of the SRC signaling pathway in BRCA2-altered mCRPC. BRCA2-null prostate cancer cell lines had increased SRC phosphorylation and higher